Gene therapy is a revolutionary development in medical care which is different from the conventional therapy. It treats disease by correction of defective gene. This treatment needs to transfer normal genes into cells. The gene delivery became a very important step for gene therapy. My research focus is on the development of non-viral gene delivery systems. Because the non-viral gene delivery system also includes different vectors, my work actually is the study of cationic liposomes. I have synthesized three series of novel cationic lipids, and found some structure-function correlation between lipids and transfection efficiency. The Computer Graphics Laboratory helps me to understand why this kind of structure is better than others.